[Postgres] "insert into ... returning id" doesn't return all generated keys when executed in a batch, but returns just 1 key/row

[salmonb]

Version

Vert.x version 4.5.7 (I also tried 4.5.8 and have the same issue)

Context

The returned RowSet should have the same number of rows as the number of tuples in List<Tuple> passed to executeBatch(), but it has only 1 row, which prevents us to get other generated keys.

Do you have a reproducer?

https://github.com/salmonb/vertx-pgreturning-issue

Steps to reproduce

See README of the reproducer

Extra

I'm on macOS Big Sur & Postgres 14.12, but also reproduced the issue on Ubuntu 22.04